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The next stage of CO2CRC Otway project involves injection of a small amount (around 15,000 tonnes) of CO2/CH4 gas mixture into saline aquifer (Paaratte formation) at a depth of ~1.5 km. The seismic time-lapse signal will depend largely on the formation properties and the injection scenario, but is likely to be relatively weak. In order to improve time-lapse seismic monitoring capabilities by decreasing the noise level, a buried receiver arrays can be used. A small-scale trial of such array was conducted at Otway site in June 2012. A set of 25 geophones was installed in 3 m deep boreholes in parallel to the same number of surface geophones. In addition, four geophones were placed into boreholes of 1 to 12 m depth. In order to assess the gain in signal-to-noise ratio and repeatability, both active and passive seismic surveys were carried out. The surveys were conducted in relatively poor weather conditions, with rain, strong wind and thunderstorms increasing the noise level. We found that noise level for buried geophones is on average 20 dB lower compared to the surface ones. Furthermore, the combination of active and passive experiments has allowed us to perform a detailed classification of various noise sources.

4D seismic is widely used to remotely monitor fluid movement in subsurface reservoirs. This technique is especially effective offshore where high survey repeatability can be achieved. It comes as no surprise that the first ...

Seismic imaging in hard rock environments is gaining wider acceptance as a mineral exploration technique and as a mine-planning tool. However, the seismic images generated from hard rock targets are complex due to high ...

Rain has long been a problem for land seismic surveys, in terms of its effect on the condition of the surface and near surface, and also due to the seismic noise it creates when raindrops hit the ground. I measured the ...